Specific changes in n-6 fatty acid metabolism in patients with chronic intestinal failure

Background and aims: In patients presenting severe malabsorption, essential fatty acid (EFA) deficiency can be corrected by intravenous lipids, but EFA abnormalities persist. The purpose of this study was to evaluate the role of large resection of the small bowel or malabsorption on plasma phospholipid EFA profile. Methods: The plasma phospholipid EFA composition was measured by gas chromatography in home parenteral nutrition patients with (n=13) or without small bowel resection (n=7) and in 14 healthy subjects. Results: The two groups of patients had the same nutritional status and comparable amounts of intravenous fat. In both groups, plasma fatty acid concentrations were significantly different from those observed in healthy subject without EFA deficiency. Among them: a decrease in 18:2n-6, 22:5n-3, 22:6n-3 and an increase in 18:3n-3, 20:4n-6, 22:4n-6. Moreover, arachidonic acid to linoleic acid ratio was higher in both groups of patients, suggesting a stimulation of the elongation and desaturation of 18:2n-6. In multiple linear regression, 18:2n-6 and 20:4n-6 levels were not associated with the small bowel length, only 22:6n-3 concentration was correlated with small bowel length. Conclusions: The patients with chronic intestinal failure on home parenteral nutrition presented specific change in their EFA and an increase in the n-6 fatty acid pathway. This could be related to the severe malabsorption.